diff --git a/emacs/.emacs.d/init.org b/emacs/.emacs.d/init.org
index 9ae5c36..9ed1ed3 100644
--- a/emacs/.emacs.d/init.org
+++ b/emacs/.emacs.d/init.org
@@ -1234,6 +1234,13 @@
                                 web-mode-markup-indent-offset 4))
    #+END_SRC
 
+   Use it for ~.html.erb~ files.
+
+   #+BEGIN_SRC emacs-lisp
+     (oni:eval-after-init
+       (add-to-list 'auto-mode-alist '("\\.html\\.erb$" . web-mode)))
+   #+END_SRC
+
 ** JavaScript
 
    Turn on electric indenting for JavaScript.